In: Statistics and Probability
   Consider a principal-agent problem with three
exogenous states of nature, θ_1,,θ_2,θ_3, two effort levels, e_L
and e_H and two output levels, distributed as follows as a function
of the state of nature and the effort level:
State of Nature   θ_1   θ_2  
θ_3
Probability   1/4   1/2   1/4
Output under e_H   18   18   1
Output under e_L   18   1   1
The principal is risk neutral, while the agent has utility function
u(w)=w^(1/2). when receiving monetary compensation w, minus the
cost of effort, which is normalized to 0 for e_L and to 0.1 for
e_H. The agent’s reservation expected utility is 0.1.
   Derive the first-best contract.
Derive the second-best contract when only output levels are observable.
   Assume the principal can buy for a price 0.1 an
information system that allows the parties to verify whether state
of nature θ_3 happened or not. Will the principal buy this
information system? Discuss.